The present invention relates to a walking assisting device for assisting walking by reducing load on user's legs.
Conventionally, as this type of walking assisting device, there is known one including a pair of left and right leg links connected to ground contact members attached to the user's left and right feet at their lower ends respectively and a load transfer portion connected to the upper ends of the leg links, wherein at least a part of the user's weight is supported by the leg links via the load transfer portion to reduce load on the user's legs so as to assist the user in walking (for example, refer to Japanese Patent Laid-Open No. 2003-220102). In this structure, the load transfer portion includes a waist support belt attached around the user's waist with the left and right leg links connected to the load transfer portion via first joints corresponding to human hip joints on both sides of the waist support belt in the lateral direction. The leg links are each formed of a freely bending and stretching link having a second joint corresponding to a human knee joint midway in the vertical direction. Moreover, a driving source for the second joint is provided to generate an assist force for supporting a part of the user's weight by means of a rotational drive of the second joint caused by the driving source.
In the conventional embodiment, however, there is a need for the user to wear the waist support belt tightly around the waist in order to transmit the assist force to the user's body reliably, and therefore the user easily has constrained feeling. Furthermore, the first joints of the left and right leg links project on both sides of the user's waist, and therefore the user easily hits his hands against the first joints or the upper parts of the leg links connected to the first joints when swinging his arms in walking, thereby reducing usability.
Furthermore, there is conventionally known a walking assisting device wherein a frame enclosing a user from the back to both sides in the lateral direction is provided with four leg links attached vertically and having wheels at lower ends and a saddle-shaped seat member which the user sits astride is mounted on the frame and wherein, after detecting a force that the user applies to the seat member, the wheels are driven so that the force becomes equal to a predetermined target value (for example, refer to Japanese Patent No. 3156367).
In this conventional embodiment, however, the device is large in size and cannot be used in a small place though the user's constrained feeling can be reduced. In addition, the user easily hits his hands against the frame when swinging his arms in walking, by which good usability is not provided.